OG Image help

Hi. I'm a noob that's trying to get an old blog up date. We converted to GeneratePress yesterday and very happy with the theme and the add-ons we've purchased. We're having a problem though with sharing to Facebook. This problem actually predates the theme switch so it probably has nothing to do with the theme (I thought our old theme was the problem, and obviously it's not.

So here's the issue. When sharing a post on FB it seems that there are no OG metatags in the post. As such no image is selected to appear as a thumbnail in FB post. Been trying to figure out why these tags aren't being generated and haven't found anything in plain english.

Note the problem happens when the image in the post is hosted on our server. If the image is hosted elsewhere it normally works fine on FB.

There was a hotlinking protection that was turned on in the CPANEL settings which I've disabled but the problem persists.

Here's a sample post:

http://babalublog.com/2015/07/22/latest-reaction-to-the-opening-of-embassies/

The error I get on the facebook debugger is:

og:image was not defined, could not be downloaded or was not big enough. Please define a chosen image using the og:image metatag, and use an image that's at least 200x200px and is accessible from Facebook.